(1) Field of the Invention
The present invention relates generally to fabric inspection systems and, more particularly, to an apparatus for inspecting a tubular knitted fabric web at high speed without operator intervention.
(2) Description of the Prior Art
In the manufacture of apparel, particularly T-shirts and the like, after the greige goods have been knit they are inspected and transferred to a finishing line. Inspection is usually accomplished by passing the fabric web in front of a light box. The light from the light box enables an operator to detect a hole or other defect in the fabric. The operator then stops the line, repairs the defect and restarts the line. If the operator misses a defect, the defect may catch inside machinery during subsequent finishing or end up in a finished garment, which must be rejected. Since the cost of a defect increases substantially as more value is put into the fabric, the lowest cost place to find a defect is just after it has been made by the knitting machine. Unfortunately, inspectors are not infallible and, in addition, are only able to reliably inspect fabric moving less than about 80 yards per minute.
Various vision inspection systems have been attempted over the years but such systems have only been able to augment the operator and have not been able to inspect fabric without the intervention of the operator. Since the operator is tied to the inspection system, he is not able to operate more than one inspection station at the same time. If the inspection station did not require the operator's attention full time, the operator could move from one machine to another and make repairs to the fabric web as needed when the inspection system identified a defect and stopped the line.
Thus, there remains a need for an apparatus for inspecting a tubular knitted fabric wed at high speed without operator intervention while, at the same time, allows an operator to make repairs and re-start inspection easily.